Treatment for the improvement of lubricating oils



Nov. 14, 1950 P. H. cARNELL 2,529,484

TREATMENT EoR THE IMPROVEMENT 0E LUBRTCATING ons Filed Dec. l5, 1947 2| 2e Pf l 25 l 27 A TTOPNE VS Patented Nov. 14, 1950 f TREATMENTFOR THE IMPROVEMENT' 0F LUBRICATINGrJ O-IVIiS 5 j Paul H'. carnelrelma, Mich.,l assif'giidr'v to Phillips., Petroleum Company, a corporation ofDelaware Application December 15, 1.94-7,..S erial' No. 7231,80L`

'7` Claims. (Cl. y1967-1173) This invention relates tothetreatrnent of 'lubricating; oils to improve. their properties.V In one ofV its. aspectsA itA relatesto. thestreatment of a.4 natural or syntheticlubricating oilA to effect; an

improvement in its properties.. Iny another aspect it relates tov the treatment of such an oil to. increasejitsV viscosity.; or viscosity index and/or to improve its color and, stability.

I have discovered that; treatment of lubricatingN oils with hydrofluoric acid andlsaturated aliphatic alcohols, at. moderatetemperatures, produces anA improvement inthe color, viscosity index, and stability of the oils... The improvement in color andi viscosity index increases with the molecular weight of the alcohol used. In one embodiment;

of. thisinvention. the moderate temperature. treatment, as stated: above, may befollowed bytreatment with a similarmixture at elevated temperatures, improvingstill further the properties ofv the lubricating oil. In another embodiment of this. invention. which still. further improves. the properties of the lubricating oil,v the above pro-V cedure, as stated inY the first; embodiment, is fol-f` lowed by. a third; step, Whichy comprises treating the lubricating oilgat, moderate temperatures With a mixture of hydrouoric acid and aliphatic alcohols as wasdone in the first step.

In. general thisl invention may be used to, im-l prove hydrocarbon materialsy within the. range ofj lubricating, oil constituents by contacting such hydrocarbon materials, inY the presence of hydro-- fluoric acid with at least one aliphatic alcohol having from 2 to 1801; more,y carbon atoms per molecule. Especially beneficial effects are obtained with saturatedj aliphaticalcohols having 110; to 18` carbon atoms per molecule.y Aliphatic alcohols are preferredto aromatic. alcohols and phenolsmbecausev of; theV deasphaltizing properties of the former. In addition, treatment of hydrocarbon materials, and particularly of lubricating oils, with hydroiuoric,acidfaliphatic'alcohol mixtures produces greater improvement in the stability of the oils than is obtained when the oils are treated With mixtures of hydrofluoric acid and aromatic oxygen containing materials,y such as. phenols and aromatic alcohols.; p l p v Itis.Sometmosadvaotaeeoos. when treatinga t lubricatingoil Withamixture of hydroluoric.l acid andiasatoretod alioheto feloohol, to add a lowooilirief paraiiinicf hydrocarbon lotteria-1,- Such as propane.. a; butanol orV aponteno. to the hydroluorio aoiol-alooholroil.mixture., such a hydrocarbon materialL may actA asasolvent to improve theseparaton of: the..- oil and the hydroluor'c acidfalcoholi layers` and may ber usedi to control; thertemperatureY oi thetreating process by being.

allowed. toevaporate. during contacting.

l In treating particular oils it is desirable touse hydrouoric acid, a. small. amounty of water, and a mixture of a majorvporltion ofy a low molecular weight aliphatic alcohol, e.g., butanol, and' a minorportion of; thelhigh` molecular Weight alcohol, e. gw., octadecanoll. Such treatment produces oils of improved color, stability, and viscosity-index. The solubility of the high molecu-- lar weight alcohol in thev low molecular WeightV alcohol simplifies handling and recovery of the high molecular Weight alcohol. High molecular Weight alcohols as described herein are alcohols* containing've or more carbon atoms.

The range ofv proportions of alcohol, oil, and hydrouoric acid use d when treating` a mixedbase. oilatv relatively. low temperatures is about 1:33 respectively, however,` this may vary when. treating other types of oil..Y The range of pro,- portionslofjoil;alcohol, andrhydrouoric acid usedwhen treatinga mixed-base. oil atelevated teme--r peratures wouldA be about 121:1 to about 1:1;3. Thus, the broadrangeot ratios is 1:1:1 to 1:3.:3. When. a mixture ofj alow, molecular Weight alcohol' and'. a. high molecular Weight alcohol is used,

they preferred. proportion is from about 1: 1 to. 10 1 Usually the required volume of` shouldlnot/,exceed about 1,0.Weigh-t per cent of' theaeidwand., preferably,y should not exceed about 5j Woiehtoerfootf en oojootfot this intention is to provide a ooit process for improving the properties of lubricating oil.

Another object is to provide a method for improving natural lubricating oils.

A further object is to provide a method of improving mixed-base lubricating oils.

A further object is to provide a method of improving the viscosity index, color, and stability of natural or synthetic lubricating oils.

Other objects and advantages of my invention will be apparent from the accompanying disclosure and discussion.

Lubricating oil as referred to herein, includes all such products and their base stocks which have a viscosity of about 75 S. U. S. (Saybolt 'Universal Seconds) at 100 F., to about 150 S. U. S. at 210 F., and as are usually understood to be covered by this term by those skilled in the art. -It

includes particularly lubricating oil stocks such as a paraffin-base stock, a naphthene-base stock, a mixed-base stock, or a synthetic-base stock, which are reiined for use as engine lubricants. By blending neutrals and bright stocks, engine lubricating oils of varying viscosity and viscosity indices are produced.

An understanding of some of the many aspects of the invention may be aided by the attached drawing, which is a schematic flow diagram illustrating the invention in one of its embodiments,

Referring now to the drawingi In the initial step a lubricating oil is introduced through line I0 to contactor II an aliphatic alcohol, preferably anhydrous, is introduced into the contactor through line I2, and hydrofluoric acid and a lowboiling parainic material are introduced into the contactor through linev I3. A portion of the parafnic material and hydrofluoric acid may be allowed to evaporate off through line I4 to condenser I6 as a means of temperature control. After a suitable contact time, of betweenzabout 5 and about 200 minutes, at a treating temperature, asY high as 100 F. but. preferably in the range of to 40 F., in contactor II, the mixture is withdrawn through line I1 to separator I8, in which the acid and hydrocarbon constituents separate into layers `as by gravity.

From separator I8 the upper lubricating oilparaiinic material layer is removed through lines I9 and 25 to ash chamber 26. If desired, a portion of the lower acid layer vmay be recycled to contactor II through lines 202 and 23, and the remaining portion removed through lines 22 and 24 to flash chamber 2 I. Also the acid layer from about 500 F. and suitable pressures to keep the hydrofluoric acid substantially liquid, with possible polymerization, condensation, alkylation, and/or disproportionation taking place. The concentration of the hydroiluoric acid in contactor 28 must be at least 85 weight per cent. If the concentration of hydrofluoric acid gets below 85 weight per cent, the acid layer may be passed through line 33 to a separate fractionator not shown, the mixture distilled and the acid recovered; or anhydrous hydrofluoric acid may be added through line 34 as needed. From contactor 28, lubricating oil, diluted hydrofluoric acid, saturated aliphatic alcohols, acid residue, and reaction products are passed to separator 36 through line 31. The upper, lubricating oil, layer from separator 36 is passed to fractionator 38 through line 39 for distillation. Low molecular weight hydrocarbon compounds from fractionator 38 are recycled through lines 35, 4I, and 21 to contactor 28. A portion or all of these low molecular weight compounds may be removed through line 35, when desired. Alcohols and other light reaction products from fractionator 38 may be recycled to contactor II through line 42, or to contactor 28 through lines 42 and 40. The lubricating oil is removed from fractionator 38 through line 43. Said lubricating oil may be washed with caustic solution to remove small amounts of hydrofluoric acid if desired. The lower layer'from separator 36, containing hydrouoric acid, water, acid residue,"and products of the process, may be passed to flash chamber 2I through lines 44 and 24, to contactor 28 through lines 44, 45,.and 33, or drawn off through line 44. WhenV a high molecular weight alcohol, e. g., octadecanol, Ais used, it is desirable to flash off. the lower molecular weight alcohols andY other light reaction products, leaving a mixture of high molecular weight alcohol and acid residue. The high molecular weight alcohol is then-separated from the acid residue by extraction with a low molecular weight alcohol, which may be introduced in any one of sevl eral inlets. Y

Various valves, pumps, Vandother conventional equipment necessary for the successful practice of this invention will be familiar'to one skilled in the art and have been omittedfrom the drawing for the sake of clarity.

separator I8 may be withdrawn through line 22,

to a purification system, not shown, if desired. From flash chamber 2|,r an overhead product comprising hydrofluoric acid, water, and light hydrouoric acid-soluble compounds is passed through lines'4I and 21 to contactor 28. The acid-soluble residue from flash chamber 2l is withdrawn through line 29 as a kettle product. In ash chamber 26 the parafnic solventis flashed ofi the lubricating oil, which is passed through lines 3I and 32 to contactor 28 or recovered as a kettle product through line 3 I. The solvent material from flash `chamber'26 is recycled through line I5 tocondenser I6 and through lines 20 and I3 to contactor II. If desired, the lubricating oil and solvent material may be passed directly from separator I8 to contactor 28 without first flashing off the solvent. The mixture in contactor 28, containing hydrofluoric acid, water, lubricating oil, saturated aliphatic alcohols, and products of the process, is agitated at elevated temperatures between about VV'100 and move the light ends.

' As'mentioned before, the process may be practiced by employing only .the low-temperature treatment or by combination of the low-temperature and high-temperature steps, as described.

Following are specific examples of the treatment of lubricating oil with a mixture of hydroiluoric acid and o-cresol, and hydrofluoric acid and aliphatic alcohols. The procedure for runs l to 4 was as follows:

A steel bomb was charged with hydrofluoricV acid, an alcohol, isopentane, 'and a mixed-base lubricating oil. The charged'bomb was clamped to aplatform rocker and agitated minutes at room temperature. The bomb was removed from the rocker and placed in a vertical position, allowing the contents to settle. The acid and hydrocarbon' layers were'separated, and the hydrocarbon layer topped at reduced pressure to the initial boiling point'of Vthe untreatedoilto re- The physical data for the product oilwere then determined.

yThe Vresults of runs showing the benefitsV to be derived from the practice'of this invention are shown in the followingtable, which lists the results of fourV combinationsof treatment` o fA mixed-base lubricatirigoils". 'f-

agissons@ Ru.. @gagged -1 snagged .2 3-1 HF, 'gram 613 ,-922 962 949 Isopentane, grams. 625 1610 621 621 Alf'hnl '0)' 0) (a) (4) Alcohol, 'grams 2 314 245 249 247 Lube oil, grams l 881 880 8 69 -880 Test Data Viscosity, '100 F. SUS 287. 3 Y'282. 5 343. 9 352. 0 i i344. 4 334. 4 Viscosity, 210 F. SUS 50. 77 50.80 v53. 39, l53. 84 53. 63, 53. 46 Viscosity Index (Dean d:

Davis) A89A 92 86 86 -88- Pour Point, oF +30 +20 +155 +15 +15 j 91 A II Gravity 28. 7 .f 29.1. 28.3 27. 5 29. 1 +10 AASTM 001er 2% 1% 2% 3 '2 29;?

Aluminum Block Stability f Data i Naphtha insolubles, Wt. i

*per cent: after heating 0.08 0.702 0.06 0. 03 0. 03 0.02 Neutralization number: j;

before heating.. 0.00 0. 01 0. 04 0.02 0.00 0.00 after heating 0.*33 0. 54 0.1-7 0.10 0.07 0. 06 lRamsbottom carbonr i wt.,per`cent: before heating 0.02 yl 0G4 --0. 0l 0.09 0.06 a'fter heating 0.21 0.1 23 `0. 21 0. 09 0. 12 0.11 Evaporation loss,

y 1 o-Cresol. 2 n-Butanol. 3 Decanol-l. 4 Oc'tadecanol. y

The data for the product oil of run4 l as .compared to the data for untreated oil A show that hydrofluoric acid-cresol treatment of .the oilproduces an oil of improved viscosity index'and color. However, the stability of the hydrofluoricacidcresol treated oil is not as good as the untreated oil which is indicated by the higher neutralization number and carbon residue for the oil after heating in the aluminum block.

The data of run 2 when compared With the properties of an untreated lubricating oil B, in which the oil was treated with hydroiluoric acid and n-butanol, show improvement, primarily in stability.

Under the treating conditions of run 3 another sample of lubricating oil B, as Compared with the untreated oil B, shows improvement in viscosity index, ASTM color, API gravity, and stability.

From comparison of data of run 4 with the untreated oil, it is seen that treating the lubricating oil With octadecanol and hydrofluoric acid improved viscosity index, pour point, API gravity, ASTM color, and stability.

It may be seen from the preceding examples that a lubricating oil is progressively improved in properties as the molecular weight of the aliphatic alcohol in the hydroiiuoric acid-alcohol treating mixture is increased. A single treatment of a lubricating oil with hydrouoric acid and one or more aliphatic alcohols at moderate temperatures improves the properties. Subsequent treating of a lubricating oil with a similar mixture of hydrofluoric acid and aliphatic alcohols at elevated temperatures followed by a third treating at moderate temperatures will increase still further the improvement of the properties of a lubricating oil.

Although the process has been described and exemplified in terms of its preferred modifications, it is understood that various changes may be made Without departing from the spirit of the process as disclosed or from the scope of the claims.

I claim:

1. The process of manufacturing a lubricating oil of improved viscosity index, color, and stability which comprises contacting a lubricating oil by thorough mingling with a mixture of at least one saturated aliphatic alcohol, hydrofluoric acid, and

water not in excess of 5 to 10 Weightper Vcent'of the hydrofluoric acid present, in the ,proportion of alcohol, oil, and hydrofluoric'acid yoi about 1:3:3 for about 5 to about 200 minutes at a sufcient pressure to maintain the hydroluoric acid substantially liquidand a temperature of about "-20 to about 40 F., and further treating said lubricating -oil with 'a mixture of at least )one saturated aliphatic alcohol, hydrofluoric acid, `and water not in excess of 5 to 10 weight per -cent of the hydrofluoric acid present, in the proportion of alcohol, oil, and hydroiiuoric acid or about 1:1:1 to about 1:1:3 for about 5 to about 200 minutes at a suilicient pressure to maintain the hydrouoric acid substantially liquidv and a tem# perature of about 'to about 500 F., and 'recov-l ering said improved lubricating oil.

2. The process of manufacturing a lubricating oil of improved viscosity index, color, and stability which comprises treating a lubricating oil by thorough mingling with a mixture of at least one saturated aliphatic alcohol, hydrofiuoric acid, and water not in excess of 5 to 10 Weight per cent of the hydrofluoric acid present, in the proportion of alcohol, oil, and hydrofluoric acid of about 1:1:1 to about 1:1:3 for about 5 to about 200 minutes at a sufficient pressure to maintain the hydroluoric acid substantially liquid and a temperature of about 100 to about 500 F.; and further treating said lubricating oil with a mixture of at least one saturated aliphatic alcohol, hydrouoric acid, and Water not in excess of 5 to 10 weight per cent of the hydrouoric acid present, in the proportion of alcohol, oil, and hydrouoric acid of about 1:3:3 for about 5 to about 200 minutes at a sufficient pressure to maintain the hydrouoric acid substantially liquid and a temperature of about -20 to about 40 F., recovering said improved lubricating oil.

3. A process of manufacturing a lubricating oil of improved viscosity index, color, and stability which comprises treating a lubricating oil by thorough mingling with a mixture of at least one saturated aliphatic alcohol, hydrouoric acid, a parainnic material, and water not in excess of 5 to 10 Weight per cent of the hydrofluoric acid present, in the proportion of alcohol, oil, and

hydrofluoric acid of about 1:3:3 for about.5 ,tom

about 200 minutes at a sufficient pressure' to,V maintain the hydrouoric acid substantially liquid and a temperature of about -20 to aboutA 40 F.; further treating said lubricating oil with a mixture of at least one saturated aliphatic alcohol, hydrofluoric acid, a paranic material, and Water not in excess of 5 to 10 Weight per cent of the hydrofluoric acid present, in the proportion of alcohol, oil, and hydrofluoric acid of i about 1:1:1 to about 1:1:3 for about 5 to about' 200 minutes at suicient pressure to maintain the hydrofluoric acid substantially liquid and at a temperature of about 100 to about 500 Fg; and further treating said lubricating oil with a mixture of at least one saturated aliphatic alcohol, hydrofiuoric acid, a parainic material, and Water not in excess of 5 to 10 weight per cent of` the hydrouoric acid present, in the proportion of alcohol, oil, and hydrofluoric acid of about 1:3:3 for about 5 to about 200 minutes at a sufficient pressure to maintain the hydrofluoric acid substantially liquid, and a temperature of about -20 to about 40 F., recovering said improved lubricating oil. Y Y

4. A process for the manufacture of improved lubricating oil which comprises contacting a lubricating oil with hydrofluoric acid and saturated aliphatic alcohol containing at least carbon atoms per molecule at a temperature in the alcohol in a ratio. in the range of 1:1 to 10:1 respectively, treating said oil at a temperature in the range of -20 to 40 F. and a contact time of V5 to200 minutes, the ratio of alcohol to oil to hydroiluoric acid lying in the range of 1:1-:1 to

lv1:3;3, and separating treating materials and acid soluble residue from the treated oil and recovering an improved lubricating oil' asa product of the process. n Vv6. A process according to claim 5 wherein not more than 5 weight per cent of water based on -.hydrouoric acid is present in the reaction mixture.V

l 7. A process for the manufacture of lubricating oil of an improved viscosity index, color, and stability, which comprises contacting a lubricating oil with hydrofiuoric acid and a saturated aliphatic alcohol containing 10 to 18 carbon atoms perV molecule at a temperature in the range of -20 to 40 F. and a contact time of 5 to 200 minutes, the ratio of alcohol to oil tohydro- I luoric acid lying in the range of 1:1:1 to 123:3,

range of -20 to 100 F. and a contact time of separating acid soluble residue from the mixture 1 of treating and treated material and further treating said oil at a temperature in the range of 100 to 500 F., maintaining the concentration of hydroluoric acid in the second treating step at not less than Weight per cent, separating treating materials from said `oil and recovering an improved lubricating oil as a product of the process.

PAUL H. CARNELL REFERENCES CITED The following references are of record in the ile of this patent:

UNITED STATES PATENTS Number Name Date A2,116,540 Roberts May 10, 1938 2,288,853 Sowers July 7, 1942 2,378,762 Frey June 19, 1945 2,440,258 Elliott et al Apr. 27, 1948 

1. THE PROCESS OF MANUFACTURING A LUBRICATING OIL OF IMPROVED VISCOSITY INDEX, COLOR, AND STABILITY WHICH COMPRISES CONTACTING A LUBRICATING OIL BY THOROUGH MINGLING WITH A MIXTURE OF AT LEAST ONE SATURATED ALIPHATIC ALCOHOL, HYDROFLUORIC ACID, AND WATER NOT IN EXCESS OF 5 TO 10 WEIGHT PER CENT OF THE HYDROFLUORIC ACID PRESENT, IN THE PROPORTION OF ALCOHOL, OIL, AND HYDROFLUORIC ACID OF ABOUT 1:3:3 FOR ABOUT 5 TO ABOUT 200 MINUTES AT A SUFFICIENT PRESSURE TO MAINTAIN THE HYDROFLUORIC ACID SUBSTANTIALLY LIQUID AND A TEMPERATURE OF ABOUT -20 TO ABOUT 40*F., AND FURTHER TREATING SAID LUBRICATING OIL WITH A MIXTURE OF AT LEAST ONE SATURATED ALIPHATIC ALCOHOL, HYDROFLUORIC ACID, AND WATER NOT IN EXCESS OF 5 TO 10 WEIGHT PER CENT OF THE HYDROFLUORIC ACID PRESENT, IN THE PROPORTION OF ALCOHOL, OIL, AND HYDROFLUORIC AND OF ABOUT 1:1:1 TO ABOUT 1:1:3 FOR ABOUT 5 TO ABOUT 200 MINUTES AT A SUFFICIENT PRESSURE TO MAINTAIN THE HYDROFLUORIC ACID SUBSTANTIALLY LIQUID AND A TEMPERATURE OF ABOUT 100 TO ABOUT 500*F., AND RECOVERING SAID IMPROVED LUBRICATING OIL. 